unlockpt --
unlock a pseudo-terminal master/slave pair
Synopsis
#include <stdlib.h>
#include <sys/ptms.h>
int unlockpt(int fildes);
Description
The function unlockpt clears a lock flag associated with the
slave pseudo-terminal device associated with its master pseudo-terminal
counterpart so that the slave pseudo-terminal device
can be opened.
fildes is a file descriptor returned from a successful open
of a master pseudo-terminal device.
Return values
Upon successful completion, the function unlockpt returns
0; otherwise it returns -1.
Errors
A failure may occur if fildes is not an open file descriptor
or is not associated with a master pseudo-terminal device.